Transient microbiota differ from normal microbiota in that transient microbiota

are present for a relatively short time.
are found in a certain location on the host.
cause diseases.
never cause disease.
are always acquired by direct contact.

are present for a relatively short time.

The yeast Candida albicans does not normally cause disease because of ______.

parasitic bacteria
the transient microbiota
the normal microbiota
other fungi

the normal microbiota

The major significance of Robert Koch’s work is that

microorganisms can be cultured.
microorganisms are present in a diseased animal.
diseases can be transmitted from one animal to another.
microorganisms cause disease.
microorganisms are the result of disease.

Which of the following is NOT a reservoir of infection?
a hospital
a healthy person
a sick animal
a sick person
None of the answers is correct; all of these can be reservoirs of infection.

None of the answers is correct; all of these can be reservoirs of infection.

Which of the following is a fomite?
insects
water
pus
a hypodermic needle
droplets from a sneeze

a hypodermic needle

Which one of the following is NOT a zoonosis?
Which one of the following is NOT a zoonosis?
cat-scratch disease
Hantavirus pulmonary syndrome
tapeworm
rabies
None of the answers is correct; all of these are zoonoses.

None of the answers is correct; all of these are zoonoses

According to the animation, surgical infections account for what percentage of nosocomial infections?
11%
40%
8%
20%
15%

20%

What type of nosocomial infection is likely to arise from intravenous catheterizations?
What type of nosocomial infection is likely to arise from intravenous catheterizations?
Cutaneous
Bacteremia
Surgical
Lower respiratory
Urinary tract

Bacteremia

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic?
Antibiotics can be used in aerosols, thereby entering the environment.
Health care workers being treated with antibiotics may pass the antibiotic on to the patient.
Visitors currently being treated with antibiotics can pass them on to the patient.

Antibiotics can be used in aerosols, thereby entering the environment.

Why are invasive procedures likely to increase the risk of nosocomial infections?
Invasive procedures must use antibiotics.
Invasive procedures require long term hospital stays, thereby increasing the number of visitors seen by the patient.
These procedures are carried out by health care workers, who carry resistant microbes.
These procedures allow microbes from the skin to enter the bloodstream of the patient.

These procedures allow microbes from the skin to enter the bloodstream of the patient.

How can health care workers reduce the occurrence of nosocomial infections?
Limit the number of visitors who can see the patient
Reduce the number of times they visit a patient
Practice more stringent aseptic techniques
Administer all medications orally instead of through injections

Practice more stringent aseptic techniques

The health of the patient
should be the primary concern of the healthcare worker.
is secondary to the health of co-workers in healthcare settings.
is secondary to the health of the healthcare worker

should be the primary concern of the healthcare worker.

How can surgeons help to limit nosocomial infections?
They should prescribe as many antibiotics as possible.
They should perform surgeries and invasive procedures only when absolutely necessary.
They should only operate on healthy individuals.
They should prescribe immunosuppressive drugs to their patients.

They should perform surgeries and invasive procedures only when absolutely necessary.

If a patient notices a healthcare worker not following suggested precautions,
they should immediately wash their hands.
they should immediately bring it to the attention of the healthcare worker.
they should leave the healthcare facility immediately.

they should immediately bring it to the attention of the healthcare worker.

Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?
Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?
Reusable
Single-use
Inexpensive
Washable
Long

Single-use

Which of the following statements is true regarding hand washing?
Hand washing should be done frequently by patients.
Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.
Hand washing should be done frequently by healthcare workers.
Hand washing should be done before and after patient interaction.

Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.

A dog develops a diarrheal disease after drinking water from a creek during a hike with his owner. Which of the following best describes this method of disease transmission?
contact transmission
vehicle transmission
vector transmission
There is not enough information to determine the mode of transmission.

vehicle transmission

Plague is transmitted through the bite of an infected flea. Which of the following best describes this mode of transmission?
direct contact transmission
vehicle transmission
indirect contact transmission
vector transmission

vector transmission

Which of the following statements about nosocomial infections is FALSE?
They may be caused by drug-resistant bacteria.
The patient was infected before hospitalization.
They may be caused by normal microbiota.
They may be caused by opportunists.
They occur in compromised patients.

The patient was infected before hospitalization.

Which of the following does NOT contribute to the emergence of infectious diseases?
Antibiotic resistance
Climatic changes
New strains of previously known agents
Ease of travel
The emergence of infectious diseases can be attributed to all of these

The emergence of infectious diseases can be attributed to all of these

Expected prevalence of a disease is
the anticipated geographical spread of a disease based on past observances.
the total number of cases of a disease over a period of time.
the expected occurrence of a disease based on past observations.
the number of new cases of a disease over a period of time.

the expected occurrence of a disease based on past observations

In the sixth segment of the animation, why is the disease epidemic in North America?
The disease occurs at a higher rate than what would normally be expected in this region.
The disease occurs at a lower rate than what would normally be expected in this region.
Only a few cases are occurring in this region.
The disease has spread to North America from Europe.

The disease occurs at a higher rate than what would normally be expected in this region.

In the last segment of the animation, how many regions of the world experience the pandemic during April of year four?
Four
Two
Six
Five

Five

In the last segment of the animation, when does the first epidemic occur?
April of year four
January of year three
January of year four
September of year three
March of year two

January of year three

If a disease occurs at a fairly stable rate, it is said to be
sporadic.
endemic.
pandemic.
epidemic.

endemic.

Epidemiology is defined as the study of
how a disease is transmitted.
when a disease occurs.
where and when a disease occurs, and how it is transmitted.
where a disease occurs.

where and when a disease occurs, and how it is transmitted.

What is the role of epidemiology?
To learn how to treat and prevent various diseases.
To learn which organisms cause disease.
To learn what diseases can be caused by respiratory pathogens.
To learn which medicines are effective at killing pathogens.

To learn how to treat and prevent various diseases.

Which of the following would be considered a fomite?
Contaminated water
A tick
An infected toy
A fly

An infected toy

Which of the following would be considered a vector?
Water droplets that come from a sneeze from an infected individual
Water containing bacteria from fecal matter
Saliva that is transmitted between individuals during kissing
A fly carrying disease from fecal matter to food

A fly carrying disease from fecal matter to food

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered
vector transmission.
contact transmission.
airborne transmission.
waterborne transmission.

contact transmission.

Which of the following is considered a major category of transmission of disease?
Vehicle transmission
Contact, vehicle, and vector transmission
Contact transmission
Vector transmission

Contact, vehicle, and vector transmission

Which is an example of vehicle disease transmission?
The presence of Listeria on undercooked chicken served for dinner
The bite of a mosquito containing malaria
Touching a telephone with cold viruses on its surface
The transmission of MRSA from skin to skin contact

The presence of Listeria on undercooked chicken served for dinner

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?
West Nile virus causes an infection and death in birds such as crows and blue jays.
West Nile virus causes a latent viral infection that can emerge later in life.
West Nile virus was first isolated in Uganda in 1937 and has caused significant outbreaks every year since then.
West Nile virus outbreaks have increased in number and affected areas since 1937.

West Nile virus outbreaks have increased in number and affected areas since 1937.

During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?
Select all that apply.
Select all that apply.
An arbovirus is an arthropod-borne virus.
An arbovirus is a virus isolated in Ann Arbor, Michigan.
An arbovirus is maintained in nature through biological transmission.
An arbovirus is a virus that originated from plants.

An arbovirus is an arthropod-borne virus.
An arbovirus is maintained in nature through biological transmission.

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill’s virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?
The students tried to isolate and identify West Nile virus from birds because they are large animals. It would be difficult to isolate West Nile virus from mosquitoes because they are small.
The students tried to isolate and identify West Nile virus from birds because they had access to dead birds that were known to be infected with West Nile virus.
The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.
The students tried to isolate and identify West Nile virus from birds because it is faster to isolate the virus from a bird than to isolate it from a mosquito.

The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?
Encephalitis is an inflammation of the meninges. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body.
Encephalitis is an inflammation of the peripheral nervous system. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body.
Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.
Encephalitis is an inflammation of the spinal cord. It is a concern to health care professionals because the infection will spread to the brain.

Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

Which of the following is the best mode of controlling the spread of West Nile infections?
Kill all mosquitoes to prevent the transmission of West Nile virus.
Kill all birds to prevent the amplification and transmission of West Nile virus.
Limit exposure to mosquitoes to prevent the transmission of West Nile virus.
Limit exposure to birds to prevent the transmission of West Nile virus.

Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

What features of West Nile virus make it an emerging disease of special concern?
Select all that apply.
West Nile virus is an arthropod-borne virus transmitted by mosquitoes.
West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America.
West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.
West Nile virus has a positive, single-stranded RNA genome that is 11,000 to 12,000 nucleotides long.

West Nile virus is an arthropod-borne virus transmitted by mosquitoes.
West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America.
West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

Etiology and Infectious Disease
In this activity students will match key terms related to etiology and infectious disease with its description.
Based on the information contained in the introduction, match each of the following concepts with its best description.

Etiology – The study of the cause of a disease.
Infectious Disease – Disease directly caused by a microorganism and not by other means, for example, genetic or degenerative disease.
Germ Theory of Disease – This theory states that microorganisms cause infectious disease.
Koch’s Postulate – Experimental requirements for identifying the agent of an infectious disease.

Experimental Approaches for Understanding Disease
In this activity students will view Foundation Figure 14.3 and determine the purpose of key aspects of this experiment: diseased or dead animal, healthy laboratory animal, microscope, and growth media.
Robert Koch performed experiments to determine the specific microorganisms associated with specific diseases.

Based on the figure, match each component in the experiment with its purpose in this experiment.

Understanding Koch’s Postulates
Student will identify Koch’s postulates for determining the etiology of infectious diseases.
Which of statements best describe Koch’s postulates?
Select all that apply.
The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal.
The same pathogen must be present in every case of the disease.
The pathogen must be isolated from the diseased host and grown in pure culture.
The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.
The microscopic properties of pathogens isolated from the original (diseased) and inoculated (also, diseased) animals should differ significantly.

The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal.
The same pathogen must be present in every case of the disease.
The pathogen must be isolated from the diseased host and grown in pure culture.
The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.

Applying Koch’s Postulates
Students will be presented with experimental results obtained when testing a suspected pathogen, and will identify appropriate conclusions based on each scenario.
A rabbit was found to have Floppy Ear disease that causes long-ear infections, but its etiology (cause) is unknown. Unknown Microorganism X from the infected rabbit’s right ear was successfully isolated and cultured on laboratory growth media. The ear of a healthy laboratory mouse was then inoculated with isolated microorganism, and after a period of time, no disease is observed. Which of the following statements BEST describe the conclusion(s) that can be drawn from this experiment?
Select all that apply.
Microorganism X modified its cell wall structure while being cultured, and is no longer infectious to rabbits.
It is not possible to isolate and culture Microorganism X in the laboratory, since this microbe is found in nature.
A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed.
Microorganism X might not be linked to Floppy Ear disease, since the inoculated mouse remained healthy.
Microorganism X is the etiologic agent for Floppy Ear disease since it caused infection in the diseased rabbit.
Healthy laboratory organisms rarely show signs and symptoms of infection and disease.

A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed.
Microorganism X might not be linked to Floppy Ear disease, since the inoculated mouse remained healthy.

Limitations to Koch’s Postulates
Students will sort statements that describe the benefits and limitations of using Koch’s postulates to determine the etiology of infectious diseases.
Sort the following statements based on whether it describes a benefit or limitation of Koch’s postulates.

Benefits – The steps are designed to systematically link a pathogen to a specific infections disease
-Healthy susceptible animals can be used as model organisms when testing many types of infections, thus avoiding the unethical inoculation of healthy human hosts.
-Laboratory findings provide experimental evidence that support the germ theory of disease
Limitation – Some infectious agents have specific growth requirements that prevent it from being artificially cultured in the laboratory.
-Different pathogens can produce the same signs and symptoms, making it difficult to determine which microorganism is causing a disease.
-Some pathogens cause several different diseases, which make it difficult to link on pathogen to one disease using Koch’s postulate.

Which of the following statements concerning pathology, infection, and disease is true?
The term infection is synonymous with the term disease.
Microorganisms that make up the normal microbiota of an individual never cause disease.
Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.
The majority of microorganisms are pathogenic.

Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

As a health care worker, I am keenly aware of how important it is to avoid harming my patients. I worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the MOST important thing I can do to avoid this?
Wash my hands before interacting with any patient.
Wear shoe covers.
Wear a lab coat.
Shave my head.

Wash my hands before interacting with any patient.

Which of the following statements about the development of infectious diseases is correct?
During the incubation period, the infected individual exhibits obvious signs of sickness.
The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).
The prodromal period is characterized by very severe symptoms.
The period of decline is the time when the infected individual’s health rapidly deteriorates.

The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).

What is the role of epidemiology?
To learn how to treat and prevent various diseases.
To learn which organisms cause disease.
To learn what diseases can be caused by respiratory pathogens.
To learn which medicines are effective at killing pathogens.